This study examined trunk muscle activation, balance and proprioception while squatting with a water-filled training tube (WT) and a traditional barbell (BB), with either closed (CE) or open eyes ...(OE). Eighteen male elite Gaelic footballers performed an isometric squat under the following conditions: BB-OE, BB-CE, WT-OE and WT-CE. The activity of rectus abdominis (RA), external oblique (EO) and multifidus (MF) was measured using electromyography, along with sway of the centre of pressure (CoP) using a force platform. Only the EO and the MF muscles exhibited an increased activity with WT (p < 0.01). In the medio-lateral direction both the velocity and range of the CoP increased significantly with WT (p < 0.01). Interestingly, the range of the CoP for the WT-CE condition was significantly lower than WT-OE (p < 0.05, d = 0.44), whilst the velocity of the CoP was marginally reduced (d = 0.29). WT elicited a greater level core muscle activation and created a greater challenge to postural stability when compared to a BB. It appears that WT does not benefit from vision but emphasises the somatosensory control of balance. The use of WT may be beneficial in those sports requiring development of somatosensory/proprioceptive contribution to balance control.
This investigation aimed to compare the international level peak intensity period of male field hockey players to those experienced during professional and amateur club hockey match play. ...Twenty-seven players from an international squad were monitored for all activity relating to field hockey over three seasons. The peak intensity period, of 3 min duration, was extracted from match play files for international and club matches. Club matches were categorised by league standard-professional vs. amateur. The output for the peak intensity period, within positions, was compared using linear mixed models (LMMs) and post hoc pairwise comparisons. Significance levels were set as
< 0.05 and Cohen's d was utilised for effect sizes. Competition level had a main effect on relative total distance
< 0.05) and significant interaction effects were found between competition level and position (
< 0.05). Midfielders competing in amateur leagues and international match play completed less relative total distance than those who compete in professional leagues (-47.88 m/min,
< 0.05), (-46.06 m/min,
< 0.05) with large effect sizes reported. No other position displayed significant differences for peak periods. Match play in professional leagues provide opportunities for midfielders to experience peak intensity periods of a greater magnitude than international match play.
Abstract
Grainger, A, Heffernan, S, Waldron, M, and Sawczuk, T. Autonomic nervous system indices of player readiness during elite-level rugby union game-week microcycles.
J Strength Cond Res
36(11): ...3173–3178, 2022—Elite-level rugby union (RU) is a high-intensity contact sport that involves large training and match volumes across a season, which can lead to postmatch fatigue. Autonomic nervous system (ANS) regulation and perceived fatigue have been suggested to relate to measures of training and match load in RU. However, there have been no studies to assess specific ANS variables in elite RU during in-season microcycles. Player readiness during game-week microcycles was measured via heart rate variability (HRV) indices, direct current potential and self-reported well-being among 13, elite, male RU players. To enable comparison, data collection days were categorized in relation to their proximity to match day, ranging from match day minus 3 (MD − 3), to match day plus 3 (MD + 3). Differences between match days were evaluated using general linear models and Cohen's
d
effect sizes. There were significant differences between MD and MD + 1 for ANS indices (RMSSD
p
= 0.04,
d
= −0.66, 95% CI 0.11–1.20; the standard deviation of NN intervals
p
= 0.04,
d
= −0.66, 95% CI 0.12–1.20; total power
p
= 0.05,
d
= −0.65, 95% CI 0.11–1.20) and wellness measures (readiness
p
= 0.18;
d
= −2.33, 95% CI, 1.54–3.13; energy
p
= 0.02;
d
= −2.24, 95% CI 1.44–3.03; soreness
p
= 0.00;
d
= −2.42, 95% CI 1.63–3.23). Match day plus 3 effects were significantly greater than MD + 1 in several ANS responses, with wellness recovering at a slower time-course than ANS responses. Measures of HRV are dysregulated postmatch, but based on their rapid recovery thereafter, using HRV to assess readiness of elite-level players in RU across a weekly microcycle could be limited and requires further investigation.
Professional rugby union is a high-intensity contact sport with position-specific high training and match volumes across a season that may lead to periods of fatigue if above a typically experienced ...threshold. This study assesses the influence of match play and/or training on fatigue levels in rugby union players.
We aimed to perform a systematic review and meta-analysis of measures used to assess fatigue status in male professional rugby union players.
Using electronic databases (PubMed, SPORTDiscus, Web of Science, Cochrane Library, EMBASE, and MEDLINE), a systematic review of fatigue testing in rugby union was conducted on (1) neuromuscular, (2) subjective self-report, (3) biochemical, and (4) heart rate-derived measures.
Thirty-seven articles were included in this systematic review, of which 14 were further included in a meta-analysis. The results of the meta-analysis revealed small, yet not significant, decreases in countermovement jump height immediately after (effect size ES = - 0.29; 95% confidence interval CI - 0.64 to 0.06), 24 h (ES = - 0.43; 95% CI - 3.99 to 3.21), and 48 h (ES = - 0.22; 95% CI - 0.47 to 0.02) after exposure to rugby union match play or training. Reported wellness (ES = - 0.33; 95% CI - 1.70 to 1.04) and tiredness (ES = - 0.14; 95% CI - 1.30 to 1.03) declined over a period of a few weeks (however, the results were not-statistically significant), meanwhile muscle soreness increased (ES = 0.91; 95% CI 0.06 to 1.75) within the 96 h after the exposure to rugby union match play or training. Finally, while cortisol levels (ES = 1.87; 95% CI - 1.54 to 5.29) increased, testosterone declined (ES = - 1.54; 95% CI - 7.16 to 4.08) within the 24 h after the exposure. However, these results were not statistically significant.
Subjective measures of muscle soreness can be used to assess fatigue after match play and training in rugby union players. Within-study and between-study variability for countermovement jump height, biochemical markers, and heart rate-derived measures means the utility (practical application) of these measures to assess fatigue in professional rugby union players after matches and training is unclear.
PROSPERO ID: CRD42020216706.
Muscle activation, peak velocity (PV) and perceived technical difficulty while using three grip variations and three loads during a deadlift exercise (DL) were examined. Twenty-nine ...resistance-trained athletes (15 males, age: 22.2 ± 2.7 years; 14 females, age: 24.8 ± 7.0 years) performed the DL with 50%, 70% and 90% of their one repetition maximum (1RM) using hook grip (HG), mixed grip (MG) and double overhand (DOH) grip. Surface electromyography (EMG) of the brachialis (BS), brachioradialis (BR) and flexor carpi ulnaris (FCU) was recorded. PV and perceived technical difficulty of each grip were also measured. Regardless of load and grip, females exhibited greater BS activation compared to males (p < 0.05; ES = 0.69) while males displayed greater BR activation, significant at 90% load (p < 0.01; ES = 1.01). MG elicited the least BR and FCU activation regardless of load and sex (p < 0.01; ES = 0.64–0.68) and was consistently ranked as the easiest grip for any load. Males achieved significantly greater PV than females at 50% and 70% (p < 0.01; ES = 1.72–1.92). Hand orientation did not significantly impact PV. A MG may be beneficial in reducing the overall perceived technical difficulty when performing a maximal DL. Athletes aiming to maximise muscle activation and potentially develop their grip strength should utilise a DOH grip or HG.
Partial body cryotherapy (PBC) has been shown to be beneficial for post-exercise recovery, however, no study has demonstrated the effectiveness of PBC as a recovery modality following elite rugby ...union (RU) training. RU is a unique sport that involves high velocity collisions with minimal protective wear and may represent a situation that could induce greater performance decrements than other sports, thus PBC could be beneficial. The application of PBC in 'real-world', as opposed to the laboratory setting, has rarely been investigated during the competitive phase of a playing season and warranted investigation.
In a counterbalanced sequential research design, professional rugby athletes (n = 18, age, 25.4 ± 4.0 years; training age, 7.2 ± 4.0 years; mass, 99.8 ± 10.6 kg and height 188.3 ± 6.0 cm) were assigned to a 12-week PBC intervention, washout period (4 weeks) and reassessed as their own controls. Total self-reported well-being, muscle soreness, sleep quality and countermovement jump (CMJ) height were assessed pre and 40 hours post 'real world' training (field and gym). Wilcoxon signed rank tests and Cohen's
were used for statistical analysis.
No differences were observed in the PBC or control conditions (
> 0.05;
0.00-0.14) for well-being (-0.02 ± 0.08% vs. 0.01 ± 0.06%), muscle soreness (-0.01 ± 0.11% vs. 0.01 ± 0.16%), sleep quality (-0.03 ± 0.14% vs 0.10 ± 0.29%) or CMJ height (36.48 to 36.59 vs 38.13 to 37.52 cm; p = 0.54).
These results suggest that the administration of PBC is ineffective at enabling the restoration of selected performance parameters during the performance maintenance phase of the competitive season. To ascertain the appropriation of its use, future investigations should seek to assess the use of cryotherapies at various phases of the elite rugby union competitive season.
Purpose
:
The well-being of elite rugby union players has been intensely scrutinised in recent years. Understanding the longitudinal development of physical traits in junior players, alongside the ...moderating effect of simultaneous increases in body mass, can aid in improving programming and ultimately help junior players prepare for the demands of senior rugby. The purpose of this study was to investigate the longitudinal physical development of elite adolescent backs and forwards in a professional rugby union academy.
Methods
:
A total of 15 players (age, 17.0 0.2 y; body mass, 90 14 kg; height, 183 9 cm; n = 7 backs, n = 8 forwards) completed anthropometric measures and 3 primary performance assessments (countermovement jump, Yo-Yo intermittent recovery test level 1, and 10-m speed) at baseline, year 2, and year 3. Mixed modelling was used to assess player development over time and differences in this development by playing position. Magnitude-based inferencing was used to assess the uncertainty in the effects.
Results
:
There was a substantial increase in countermovement jump height for both groups combined (0.9, ±0.4; standardized improvement, ±90% confidence limits; most likely substantial). Forwards exhibited a moderate-sized decrease in speed (−1.0, ±0.5; very likely substantial), and there was a large difference between groups with regards to speed change with backs outperforming forwards (1.5, ±0.9; very likely substantial). For forward, body mass change had a large negative association with 10-m speed (−1.9, ±0.7; most likely substantial) and Yo-Yo intermittent recovery test level 1 change (−1.2, ±0.9; very likely substantial).
Conclusion
:
These findings provide novel normative data for longitudinal changes in junior rugby union players and suggest that coaches should account for changes in body mass when targeting increases in speed and aerobic fitness.
To assess the magnitude of change and association with variation in training load of two performance markers and wellbeing, over three pre-season training blocks, in elite rugby union athletes.
...Observational.
Twenty-two professional players (age 25±5 years; training age 6±5 years; body mass, 99±13kg; stature 186±6cm) participated in this study, with changes in lower (CMJ height) and upper body (bench press mean speed) neuromuscular function and self-reported wellbeing (WB) assessed during an 11-week period.
There was a small increase in CMJ height (0.27, ±0.17 – likely substantial; standardised effect size, ±95% confidence limits – magnitude-based inference) (p=0.003), bench press speed (0.26, ±0.15 – likely substantial) (p=0.001) and WB (0.26, ±0.12 – possibly substantial) (p<0.0001) across the pre-season period. There was a substantial interaction in the effect of training load on these three variables across the three training phases. A two-standard deviation (2SD) change in training load was associated with: a small decrease in CMJ height during the power phase (−0.32, ±0.19 – likely substantial) (p=0.001); a small reduction in bench press speed during the hypertrophy phase (−0.40, ±0.32 – likely substantial) (p=0.02); and a small reduction in WB during the strength phase (−0.40, ±0.24 – very likely substantial) (p<0.0001). The effects of changes in training load across other phases were either likely trivial, only possibly substantial, or unclear.
The effect of training load on performance can vary both according to the type of training stimulus being administered and based on whether upper- or lower-body outcomes are being measured.
The purpose of this study was to describe the locomotor activity of men's hockey based on the phase of play and to identify if differences in locomotor activity exist between phases. Twenty-four ...players (age 26 ± 4) wore a 10 Hz Global Positioning System device to track locomotor activity during 10 international matches. The locomotor activity of players was allocated to five different phases: (1) established attack, (2) opposition counterattack, (3) established defence, (4) attacking counterattack and (5) offensive pressing, utilising a video analysis-based system. Linear mixed models and post-hoc pairwise comparisons, using estimated marginal means, were utilised to compare the locomotor activity in each phase of play within each position. Significant main effects were found for the phase of play on several locomotor activity metrics (p ≤ 0.05). With respect to max speed and relative total distance across positions, counterattacks present a unique challenge compared to other phases. Established attack phases evoke lower max speed values than offensive pressing phases for all playing positions as well as compared to opposition counterattacks for defenders, midfielders, and forwards. Positional differences existed during attacking counterattack phases, with defenders producing lower values than both midfielders and forwards for high-speed running, high-speed running efforts, max speed and relative total distance. Depending on the metric, this approach captured 22%–70% of a player's locomotor activity providing valuable insight into the current dynamics of international hockey. This investigation demonstrated positional differences based on the phase of play, which may explain previous research findings regarding positional differences.
The aim of this study was to identify position-related differences in absolute and relative match impacts in rugby union. Thirty-eight subjects were tracked, using GPS units containing inertial ...sensors, across one full playing season (n = 462 data sets). No difference in the number of impacts >9.01 G were observed between forwards (229 ± 160) and backs (226 ± 151). Forwards, however, experienced a greater absolute (p = 0.03) and relative (p = 0.003) number of impacts >13 G compared to backs. Full backs experienced the highest frequency of absolute impacts >9.01 G, which was significantly greater compared to locks (p = 0.001, d = 1.84), back row (p = 0.003, d = 0.68), out half (p = 0.036, d = 1.24) and wingers (p = 0.036, d = 0.76). Hookers experienced the highest relative frequency of impacts >9.01 G, which was significantly greater than locks (p < 0.001, d = 2.06), back row (p = 0.001, d = 1.10), outside halves (p = 0.001, d = 1.44) and wingers (p < 0.001, d = 1.19). Coaches should consider these findings when planning training sessions, as the frequency and magnitude of impacts experienced by positional groups vary during match play.
PDF
